Toto Wolff says he remains in "regular contact" with Formula 1 legend Niki Lauda.
Together, the duo own and run F1's highly successful works Mercedes team. Some weeks ago, 69-year-old team chairman Lauda had a life-saving lung transplant.
He continues to recover in a Vienna hospital, and Mercedes boss Wolff said "everyone" at the team misses him.
"For me I especially miss him from the human point of view. As a travel companion, a sparring partner and a friend.
It was important that we always had dinner in the evening to discuss the day - just the two of us. At the moment I have lost a very important contact person or opposite pole," Wolff told Die Welt newspaper.
Wolff says he is keeping the F1 legend up to date with the goings on in F1 and at Mercedes.
"His health is the most important thing for now, so he needs rest, but I'm in regular contact with him. He watches all the races and I try to keep him up to date as much as possible," he said.
